The US has put in place, from January of this year, an electronic travel registration system for visitors (tourists) to the USA, coming from the Visa Waiver Program countries.
A list of these countries, and information about the program, can be found here
The ESTA registration is FREE. There is NO CHARGE for the ESTA registration, and if you are approved, the registration is valid for two years. That doesn't mean you can stay in the US for two years, it means you don't have to register with ESTA for that time.
More specific info is here
, in the ESTA FAQ.
There are numerous websites that claim to be the ESTA registration at the moment. The most infamous one is www.ESTA.US
. This is a commercial service, seemingly to "help" you register for an ESTA travel authorization. They have the look and feel of a government website, and will even inform you that having a third party complete your ESTA registration may complicate your process. You should only do it yourself, they say, that being on their website and by paying their fee (USD 49.95).
There are other such "services" out there. If you use one of them, you can not be sure that the application has been filed, and you are risking deportation when you arrive in the US, denied entry, and later Visa application problems.
The ESTA registration MUST be filled out here; https://esta.cbp.dhs.gov/
This is the US Government site for ESTA applicants. Your ESTA application should NEVER be filled out ANYWHERE else. Remember to follow the instructions precisely.
Again, the ESTA application process is mandatory for people visiting the US as tourists, coming from the VWP countries. The ESTA application should be filled out here: https://esta.cbp.dhs.gov/
- and nowhere else. The ESTA application is FREE of charge. If you are asked to pay for it, you are being scammed.